Cloning and Characterization of the nagA Gene That Encodes Beta-N-Acetylglucosaminidase From Aspergillus Nidulans and Its Expression in Aspergillus Oryzae

Biosci Biotechnol Biochem. 2002 Oct;66(10):2168-75. doi: 10.1271/bbb.66.2168.


We isolated a beta-N-acetylglucosaminidase encoding gene and its cDNA from the filamentous fungus Aspergillus nidulans, and designated it nagA. The nagA gene contained no intron and encoded a polypeptide of 603 amino acids with a putative 19-amino acid signal sequence. The deduced amino acid sequence was very similar to the sequence of Candida albicans Hex1 and Trichoderma harzianum Nag1. Yeast cells containing the nagA cDNA under the control of the GAL1 promoter expressed beta-N-acetylglucosaminidase activity. The chromosomal nagA gene of A. nidulans was disrupted by replacement with the argB marker gene. The disruptant strains expressed low levels of beta-N-acetylglucosaminidase activity and showed poor growth on a medium containing chitobiose as a carbon source. Aspergillus oryzae strain carrying the nagA gene under the control of the improved glaA promoter produced large amounts of beta-N-acetylglucosaminidase in a wheat bran solid culture.

MeSH terms

  • Acetylglucosaminidase / genetics*
  • Amino Acid Sequence
  • Aspergillus nidulans / enzymology*
  • Aspergillus nidulans / genetics*
  • Aspergillus oryzae / enzymology*
  • Aspergillus oryzae / genetics*
  • Base Sequence
  • Cloning, Molecular
  • Culture Media
  • Dietary Fiber
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression Regulation, Enzymologic / genetics*
  • Gene Expression Regulation, Fungal / genetics*
  • Genes, Fungal / genetics*
  • Molecular Sequence Data
  • Reverse Transcriptase Polymerase Chain Reaction
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism


  • Culture Media
  • Dietary Fiber
  • Acetylglucosaminidase